[PBQP] Use DenseSet rather than std::set for PBQP's PoolCostAllocator

implementation.

This is good for a ~6% reduction in total compile time on the nightly test suite
when running with -regalloc=pbqp.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220183 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/PBQP/Math.h

@@ -10,6 +10,7 @@
 #ifndef LLVM_CODEGEN_PBQP_MATH_H
 #define LLVM_CODEGEN_PBQP_MATH_H
 
+#include "llvm/ADT/Hashing.h"
 #include <algorithm>
 #include <cassert>
 #include <functional>
@@ -21,7 +22,7 @@ typedef float PBQPNum;
 
 /// \brief PBQP Vector class.
 class Vector {
-  friend class VectorComparator;
+  friend hash_code hash_value(const Vector &);
 public:
 
   /// \brief Construct a PBQP vector of the given size.
@@ -137,21 +138,12 @@ private:
   PBQPNum *Data;
 };
 
-class VectorComparator {
-public:
-  bool operator()(const Vector &A, const Vector &B) {
-    if (A.Length < B.Length)
-      return true;
-    if (B.Length < A.Length)
-      return false;
-    char *AData = reinterpret_cast<char*>(A.Data);
-    char *BData = reinterpret_cast<char*>(B.Data);
-    return std::lexicographical_compare(AData,
-                                        AData + A.Length * sizeof(PBQPNum),
-                                        BData,
-                                        BData + A.Length * sizeof(PBQPNum));
-  }
-};
+/// \brief Return a hash_value for the given vector.
+inline hash_code hash_value(const Vector &V) {
+  unsigned *VBegin = reinterpret_cast<unsigned*>(V.Data);
+  unsigned *VEnd = reinterpret_cast<unsigned*>(V.Data + V.Length);
+  return hash_combine(V.Length, hash_combine_range(VBegin, VEnd));
+}
 
 /// \brief Output a textual representation of the given vector on the given
 ///        output stream.
@@ -167,11 +159,10 @@ OStream& operator<<(OStream &OS, const Vector &V) {
   return OS;
 }
 
-
 /// \brief PBQP Matrix class
 class Matrix {
 private:
-  friend class MatrixComparator;
+  friend hash_code hash_value(const Matrix &);
 public:
 
   /// \brief Construct a PBQP Matrix with the given dimensions.
@@ -385,24 +376,12 @@ private:
   PBQPNum *Data;
 };
 
-class MatrixComparator {
-public:
-  bool operator()(const Matrix &A, const Matrix &B) {
-    if (A.Rows < B.Rows)
-      return true;
-    if (B.Rows < A.Rows)
-      return false;
-    if (A.Cols < B.Cols)
-      return true;
-    if (B.Cols < A.Cols)
-      return false;
-    char *AData = reinterpret_cast<char*>(A.Data);
-    char *BData = reinterpret_cast<char*>(B.Data);
-    return std::lexicographical_compare(
-             AData, AData + (A.Rows * A.Cols * sizeof(PBQPNum)),
-             BData, BData + (A.Rows * A.Cols * sizeof(PBQPNum)));
-  }
-};
+/// \brief Return a hash_code for the given matrix.
+inline hash_code hash_value(const Matrix &M) {
+  unsigned *MBegin = reinterpret_cast<unsigned*>(M.Data);
+  unsigned *MEnd = reinterpret_cast<unsigned*>(M.Data + (M.Rows * M.Cols));
+  return hash_combine(M.Rows, M.Cols, hash_combine_range(MBegin, MEnd));
+}
 
 /// \brief Output a textual representation of the given matrix on the given
 ///        output stream.
@@ -410,7 +389,7 @@ template <typename OStream>
 OStream& operator<<(OStream &OS, const Matrix &M) {
   assert((M.getRows() != 0) && "Zero-row matrix badness.");
   for (unsigned i = 0; i < M.getRows(); ++i)
-    OS << M.getRowAsVector(i);
+    OS << M.getRowAsVector(i) << "\n";
   return OS;
 }
 
@@ -424,6 +403,11 @@ private:
   Metadata md;
 };
 
+template <typename Metadata>
+inline hash_code hash_value(const MDVector<Metadata> &V) {
+  return hash_value(static_cast<const Vector&>(V));
+}
+
 template <typename Metadata>
 class MDMatrix : public Matrix {
 public:
@@ -434,6 +418,11 @@ private:
   Metadata md;
 };
 
+template <typename Metadata>
+inline hash_code hash_value(const MDMatrix<Metadata> &M) {
+  return hash_value(static_cast<const Matrix&>(M));
+}
+
 } // namespace PBQP
 } // namespace llvm